In solid-state imaging devices, a single-slope type, pipeline type, or successive-approximation type of AD conversion circuit is provided for each column of a plurality of pixels arranged in rows and columns, and the AD conversion circuit AD-converts an analog signal from each pixel of the column to produce a digital signal. The pipeline type or successive-approximation type of AD conversion circuit of these AD conversion circuits compares a reference voltage and the analog signal of the pixel, thereby converting the analog signal of the pixel into a digital value. A configuration is disclosed where a programmable gain amplifier (PGA) circuit for amplifying the analog signal from the pixel cell is provided in order to adjust the brightness of video outputted from the solid-state imaging device in the above-mentioned conversion, but with this configuration, an equal number of PGA circuits to the number of vertical pixel columns are necessary. For the purpose of reducing the cost of realizing the solid-state imaging device, it is desired to enable gain adjustment without providing PGA circuits.